VTA ST120 and Infinity Kappa 7's

What are your thoughts on driving a set of infinity kappa 7's with the ST120?
I'm currently running KT88's and am thinking about going to KT120's
I do run the KT88's kinda hot with a bias of .55 to .60.

Why do you run them hotter? Tubes can last a lot longer and still sound good at 0.40 volts.

They seem to sound much better to me this way in the rig I've been using it in. My last set of tubes, EH6550's, lasted 4 years at about 4000 hours set like this. Obviously this is by my ear but it seems to give me what in looking for.